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Tuesday, March 18, 2014

When To Fertilize?

As the temperatures begin to rise and Spring is in the air, its only natural to start thinking about outdoor projects - which usually include tackling that lawn that was neglected all winter long.

This article was provided to us by Russell Landscape and was written by Clint Waltz, a PhD and Turfgrass Specialist at UGA. It provides great insight as to when the best time to fertilize your lawn may be. If you have any additional questions, be sure to contact your local garden store or your professional landscape company.

Spring Timing for Warm-season Turfgrass
Fertilization

Clint
Waltz, Ph.D., Turfgrass Specialist, The University of
Georgia

This time of year we start seeing marketing and commercials
promoting “now” is the time to fertilize lawns. Homeowners need to know the
proper timing for the spring nitrogen application to warm-season grasses like
bermudagrass and zoysiagrass. Remember
that nitrogen (N) is the first number on a fertilizer bag. Simply,
nitrogen should not be applied to warm-season grasses until the soil
temperatures at the 4-inch depth are consistently 65° F and rising. For areas north of Atlanta these
environmental conditions may not occur until mid-April. Also, waiting on proper soil temperatures
allows the grass to green-up on its own, typically better than forcing the
grass to green-up too soon.

Four reasons for withholding nitrogen until late spring
include:

1. Good Agronomics – when soil
temperatures are below 65° F there is little, to no, root activity for
warm-season grasses. Why apply nitrogen
when the grass cannot use it?

2. Environmental – if not taken-up by the
plant, nitrogen can leach through the soil or be lost by runoff. Why apply nitrogen when the grass cannot take
it up and risk contaminating water bodies?

3. Pest Management – nitrogen
fertilization during green-up can make the grass more susceptible to diseases,
insects, and open voids in the canopy for weeds to establish. Why apply nitrogen at a time when the grass
is more sensitive to pests?

4. Economic – when a nitrogen application
is mistimed it can be inefficient and costly.
Why spend the money on nitrogen when the grass roots cannot take it up, it
can move out of the root zone becoming an environmental hazard, or lead to pest
issues that become an additional cost to treat?

To determine if environmental conditions are favorable for
spring nitrogen, monitor soil temperatures in your own lawn with a 4- to 6-inch
soil thermometer or, visit www.GeorgiaWeather.net
to get local environmental conditions.

If your lawn is a combination of bermudagrass and tall
fescue, a cool-season species, the two areas in the lawn should be fertilized
independently and when the environmental conditions are ideal for each
species. Late February or early March is
good for tall fescue but not bermudagrass and zoysiagrass.

Following these simple guidelines for warm-season grasses
can lead to healthier lawns, reduced environmental impacts, and less cost.